Chapter 1 System analysis fundamentals

1. Chapter 1System analysis fundamentals

2. Major Topics • Information systems • Phases of analysis and design • System maintenance • CASE tools • Alternate methodologies • Question format • Interviewing techniques • Joint Application Design (JAD) • Questionnaires

3. Information • Information is an organizational resource, which must be managed as carefully as other resources. • Costs are associated with information processing. • Information processing must be managed to take full advantage of its potential.

4. Categories Information systems fall into one of the following eight categories: • Transaction processing systems (TPS). • Office automation systems (OAS). • Knowledge work systems (KWS). • Management information systems (MIS). • Decision support systems (DSS). • Expert systems (ES) and Artificial Intelligence (AI). • Group decision support systems (GDSS) and Computer-Supported Collaborative Work Systems. • Executive support systems (EES).

5. New Technologies New technologies are being integrated into traditional systems: • Ecommerce uses the Web to perform business activities. • Enterprise Resource Planning (ERP) has the goal of integrating many different information systems within the corporation. • Wireless and handheld devices, including mobile commerce (mcommerce). • Open source software.

7. Advantages of Using the Web • The benefits of using the Web are: • Increasing awareness of the availability of the service, product, industry, person, or group. • 24-hour access for users. • Standard interface design. • Creating a global system.

8. Nature of Analysis and Design Systems analysis and design is a systematic approach to: • Identifying problems, opportunities, and objectives. • Analyzing the information flows in organizations. • Designing computerized information systems to solve a problem.

9. Systems Analyst • Systems analysts act as: • Outside consultants to businesses. • Supporting experts within a business. • As change agents. • Analysts are problem solvers, and require communication skills. • Analysts must be ethical with users and customers.

10. Systems Development Life Cycle • The systems development life cycle is a systematic approach to solving business problems. • It is divided into seven phases. • Each phase has unique activities.

12. Phase 1 • Identifying: • Problems. • Opportunities. • Objectives. • Personnel involved: • Analyst. • User management. • Systems management.

13. Phase 2 • Determining information requirements: • Interview management, operations personnel. • Gather systems/operating documents. • Use questionnaires. • Observe the system and personnel involved. • Learn the who, what, where, when, and how, and the why for each of these.

14. Phase 2 (Continued) • Personnel involved: • Analyst. • User management. • User operations workers. • Systems management.

15. Phase 3 • Analyzing system needs: • Create data flow diagrams. • Document procedural logic for data flow diagram processes. • Complete the data dictionary. • Make semistructured decisions. • Prepare and present the system proposal. • Recommend the optimal solution to management.

16. Phase 3 (Continued) • Personnel involved: • Analyst. • User management. • Systems management.

17. Phase 4 • Designing the recommended system: • Design the user interface. • Design output. • Design input. • Design system controls. • Design files and/or database. • Produce program specifications. • Produce decision trees or tables.

18. Phase 4 (Continued) • Personnel involved: • Analyst. • System designer. • User management. • User operations workers. • Systems management.

19. Phase 5 • Developing and documenting software: • Design computer programs using structure charts, Nassi-Schneiderman charts, and pseudocode. • Walkthrough program design. • Write computer programs. • Document software with help files, procedure manuals, and Web sites with Frequently Asked Questions.

20. Phase 5 (Continued) • Personnel involved: • Analyst. • System designer. • Programmers. • Systems management.

21. Phase 6 • Testing and maintaining the system: • Test and debug computer programs. • Test the computer system. • Enhance system.

22. Phase 6 (Continued) • Personnel involved: • Analyst. • System designer. • Programmers. • Systems management.

23. Phase 7 • Implementing and evaluating the system: • Plan conversion. • Train users. • Purchase and install new equipment. • Convert files. • Install system. • Review and evaluate system.

24. Phase 7 (Continued) • Personnel involved: • Analyst. • System designer. • Programmers. • User management. • User operations workers. • Systems management.

25. Rapid Application Development Rapid Application development (RAD) is an object-oriented approach to systems development.

26. System Maintenance • System maintenance is: • Removing undetected errors, and • Enhancing existing software. • Time spent on maintenance typically ranges from 48-60 percent of total time.

28. System Enhancements Systems are enhanced for the following reasons: • Adding additional features to the system. • Business and governmental requirements change over time. • Technology, hardware, and software are rapidly changing.

30. CASE Tools • CASE tools are automated, microcomputer-based software packages for systems analysis and design. • Four reasons for using CASE tools are: • To increase analyst productivity. • Facilitate communication among analysts and users. • Providing continuity between life cycle phases. • To assess the impact of maintenance.

31. CASE Tool Categories CASE tools may be divided into several categories • Upper CASE (also called front-end CASE) tools, used to perform analysis and design. • Lower CASE (also called back-end CASE). These tools generate computer language source code from CASE design. • Integrated CASE, performing both upper and lower CASE functions.

32. Upper CASE Upper CASE tools: • Create and modify the system design. • Store data in a project repository. • The repository is a collection of records, elements, diagrams, screens, reports, and other project information. • These CASE tools model organizational requirements and define system boundaries.

33. Lower CASE • Lower CASE tools generate computer source code from the CASE design. • Source code may usually be generated in several languages.

34. Advantages of Generating Code • Time to develop new systems decreases. • The time to maintain generated code is less than to maintain traditional systems. • Computer programs may be generated in more than one language. • CASE design may be purchased from third-party vendors and tailored to organizational needs. • Generated code is free from program coding errors.

36. Reverse Engineering • Reverse engineering is generating the CASE design from computer program code. • Source code is examined, analyzed, and converted into repository entities.

37. Reverse Engineering (Continued) • Reverse engineering produces (depending on the tool set used): • Data structures and elements, describing the files, records, and field. • Screen designs, if the program is online. • Report layouts for batch programs. • A structure chart showing the hierarchy of the modules in the program. • Database design and relationships.

38. Advantages of Reverse Engineering Reverse Engineering has the following advantages: • Reduced system maintenance time. • Program documentation is produced for loosely documented programs. • Structured programs may be generated from unstructured, older programs. • Future system maintenance is easier to implement. • Unused portions of programs may be eliminated.

39. Object-Oriented Analysis and Design • Object-oriented (O-O) analysis and design is used to build object-oriented programs. • O-O programming examines the objects of a system. • Objects are grouped into classes for optimal reuse and maintainability.

40. The Unified Modeling Language • The Unified Modeling Language (UML) is an industry standard for modeling object-oriented systems. • It breaks down a system into a use case model.

41. Extreme Programming (XP) • Extreme programming takes good software development practices and pushes them to the limit. • It is based on: • Values. • Principles. • Core practices.

42. Extreme Programming (XP) (Continued) • Extreme programming values are: • Communication. • Simplicity. • Feedback. • Courage.

43. Alternate Methodologies • Alternate methodologies are available for analyzing systems. • These include: • Prototyping. • ETHICS. • Project Champions. • Soft Systems Methodology. • Multi-view.

44. Interviewing • Interviewing is an important method for collecting data on information system requirements. • Interviews reveal information about: • Interviewee opinions. • Interviewee feelings. • About the current state of the system. • Organizational and personal goals. • Informal procedures.

45. Planning the Interview Five steps in planning the interview are: • Reading background material. • Establishing interview objectives. • Deciding whom to interview. • Preparing the interviewee. • Deciding on question types and structure.

46. Question Types There are two basic types of interview questions: • Open-ended. • Closed.

47. Open-Ended Questions • Open-ended interview questions allow interviewees to respond how they wish, and to what length they wish. • Open-ended questions are appropriate when the analyst is interested in breadth and depth of reply.

48. Advantages of Open-Ended Questions Eight benefits of open-ended questions are: • Puts the interviewee at ease. • Allows the interviewer to pick up on the interviewee's vocabulary. • Reflect education, values, attitudes, and beliefs. • Provides richness of detail. • Reveals avenues of further questioning that may have gone untapped.

49. Advantages of Open-Ended Questions Eight Benefits of open-ended questions are: (continued) • Provides more interest for the interviewee. • Allows more spontaneity. • Makes phrasing easier for the interviewer. • Useful if the interviewer is unprepared.

50. Disadvantages of Open-Ended Questions The five drawbacks include: • May result in too much irrelevant detail. • Possibly losing control of the interview. • May take too much time for the amount of useful information gained. • Potentially seeming that the interviewer is unprepared. • Possibly giving the impression that the interviewer is on a "fishing expedition”